1. Field of the Invention
The present invention relates to a noncontact measurement method, and more particularly to a noncontact measurement method which can measure currents flowing through a plurality of superconductive wires connected in parallel using hall sensors in a noncontact manner.
2. Description of the Related Art
After the introduction of a superconductive wire or a High Temperature Superconductor (HTS) wire, intensive studies have been made to develop power-related equipment using the superconductive wire.
In contrast to general power equipment using copper, superconductive power equipment requires a cooling facility to maintain the characteristics of the superconductive wire. Thus, in order to achieve superconductive power equipment, which is economically efficient compared to general power equipment, it is necessary to develop wires which can be applied to highly efficient, large-capacity power equipment.
The use of wires, each including multiple superconductive wires connected in parallel, to manufacture large-capacity power equipment has been suggested taking into consideration the fact that the threshold current of a second generation superconductive wire, which is currently under study, is less than about 250 A. Among a variety of superconductive wires developed until now, a 1 cm-wide YBCO wire which has been recently developed has the threshold current of about 280 A. However, a number of superconductive wires must be connected in parallel to be used for large-capacity high-temperature, superconductive power equipment since the large-capacity power equipment requires currents of hundreds or thousands of Ampere.
When a coil is manufactured using a wire constructed by connecting superconductive wires in parallel, which will be referred to as a “parallel wire”, the levels of each current flowing through each superconductive wire included in the parallel wire may not be uniform due to different impedances of each superconductive wire.
Such unbalance-distribution of current throughout the parallel wires causes a reduction in the conductive current that can flow through the parallel wire and an increase in the AC loss. Thus, in order to increase the conductive current and to decrease the AC loss, it is necessary to make the distribution of current throughout the superconductive wires included in the parallel wire uniform.